Tunneling wheel



L. F. SCOTT TUNNELING WHEEL Dec. 6, 1966 5 SheetsSheet 1 Original Filed Dec. 27, 1960 Dec. 6, 1966 F. SCOTT 3,290,093

TUNNELING WHEEL Original Filed Dec. 27, 1960 5 Sheets-Sheet z WILL Imam 772,6

Dec. 6, 196 6 L. F. SCOTT 3,290,098

TUNNELING WHEEL Original Filed Dec. 27, 1960 5 Sheets-Sheet 5 Xmef/v E f rr fly 4 4 1 42,4450 fufTTA EB)" l/LLMMN United States Patent Office 3,290,098 Patented Dec. 6, 1966 469,754 5 Claims. (Cl. 299-90) The present invention relates to means for forming tunnels, especially large diameter tunnels for use as storm drains and the like. I

This application is a division of my copending applicatron Serial No. 78,487, filed December 27, 1960; which discloses a tunneling machine employed to drive a 13- foot diameter tunnel through earth, and also employed to drive smaller lateral tunnels or spurs, such as '7, 8 and 10 foot diameter tunnels.

The machine is comprised essentially of a horizontal beam-like frame adapted to extend .longitudinally of the tunnel, a rotatable excavating wheel of a diameter considerably larger than the frame journalled on the forward end of the frame in a plane perpendicular to the axis of the frame and with its axis adjacent and parallel to the frame axis, the wheel having excavating teeth on its front face for cutting a circular hole in the ground, a supporting structure for the frame and wheel comprising collar means slidably engaging about the frame and jacks extending horizontally outward from the collar means for engagement with the tunnel walls to secure the supporting structure in the tunnel, and wheel crowding means connected between the frame and the supporting structure for crowding the frame and wheel forwardly relative to the supporting structure when the latter is locked in the tunnel. Also, the frame includes a pair of depending jack means for supporting the frame in the tunnel so that the horizontal jacks can be released from the tunnel walls and the collars can be advanced on the frame when necessary. The mode of operation of the machine is essentially as follows: After a vertical manhole shaft has been formed and the tunnel has been started by hand, the machine is lowered from the surface through the manhole into the tunnel. The front face of the wheel is engaged with the face of the tunnel for continuation of the tunnel to specifications. In general, the wheel is of the same diameter as the tunnel and the frame extends generally axially rearward therefrom. The collars are then advanced forwardly on the frame and the horizontal jacks are projected outwardly to gain a firm purchase on the tunnel walls, whereby said supporting structure is fixed in the tunnel. The wheel is set in operation and the crowding means are actuated to force the wheel and frame forwardly against the face of the tunnel to cut or excavate the earth. Preferably, a conveyor is ,provided on the frame for carrying excavated materials from the wheel to the rear end of] the frame where the conveyor may discharge into muck cars or any other suitable means for removing the materials from the tunnel.

and frame are advanced, the same .are accurately guided by said supporting structure. When the wheel and frame have been advanced to the limit accommodated between the supporting structure and the frame, the depending jacks on the frame are lowered to support the frame As the wheel vanced step-by-step to form the tunnel, and it may be employed with facility to form both straight and curved tunnels and to establish and maintain any specified tunnel grade. I

The object of the present invention is the provision of improved excavating wheels for tunneling machines of the character above described, said wheel comprising a disc-like hub, a surrounding annular shell, and a plurality of generally radial arms extending between and secured to said disc and said shell, some of said arms carrying cutters and the other of said arms carrying excavating blades, said blades collectively spanning substantially the entire radial distance between said disc and said shell,

said cutters being located respectively substantially the same radial distance from said disc as the inside edge of one blade and the outside edge of another and projecting further outward in the axial direction than said blades.

A still further object of the invention is the provision of excavating blades as above defined characterized by disposition of the same at a cutting angle in the order of about 47 /2 degrees.

Other objects and advantages of the invention will become apparent in the following detailed description.

Now, in order to acquaint those skilled in the art with the manner of making and using my excavating or tunneling wheel, I shall describe, in connection with the accompanying drawings, a preferred embodiment of the wheel and a preferred manner of making and using the same.

In the drawings:

FIGURE 1 is a perspective view of a preferred embodiment of a tunneling machine including my improved wheel;

FIGURE 2 is a fragmentary front elevation of the wheel, the view showing by shaded and unshaded annular areas the paths of the excavating blades and cutters;

FIGURE 3 is a plan view of one of the excavating blades showing the cutting angle of the same relative to the face of the Wall being excavated;

FIGURE 4 is a plan view of one of the excavating cutters; 1

FIGURE 5 is a side view of one of the excavating blades, the view being taken substantially on line 55 of FIGURE 3-.

FIGURE 6 is a side view of one of the excavating cutters, the view being generally similar to FIGURE 5;

FIGURE 7 is a fragmentary longitudinal section of the forward end of the machine frame and the excavating wheel; and

FIGURE 8 is a fragmentary perspective view of the wheel shell showing one of the mounting blocks for the blade and cutter carrying arms.

Referring now to the drawings, and particularly to FIG- URE 1, the preferred embodiment of my tunneling machine is shown as comprising an excavating wheel 20, a relatively small diameter frame 22 extending generally axially rearward from the wheel, a supporting and guiding structure 24 for the frame, supporting jacks 26 for the frame and a conveyor 28 mounted above the frame and extending from the wheel to the rearward end of the frame.

The frame 22 preferably comprises an elongate rigid steel tube, suitably about 20 inches in diameter, having longitudinally extending guide tracks 30 on its upper and lower surfaces adjacent its opposite ends. At its forward end, as shown in FIGURE 7, the tube 22 rigidly mounts therein a short tubular bearing member 32 which extends through and is secured to a vertical frame plate 34 that is secured to the front face of the tube 22 perpendicular thereto. The bearing 32 is disposed parallel to the tube axis but is eccentric thereto, and the same is preferably set vertically and centrally above the axis of the tube substantially to the full extent accommodated by cular central wheel hub or disc 44 which is reinforced by a plurality of triangular radial gusset plates 46 secured to the shaft and the disc forwardly of the disc. On its rearward surface, the disc 44 mounts an internally toothed ring gear 48 (FIG. 1) by means of which the wheel 20 is rotated.

The wheel drive mechanism is mounted on and extends through the frame plate 34 above and preferably to one side of the tube 22, the mechanism comprising a pair of high torque electric motors 50, suitably 300 volt, 120 cycle, 90 horsepower motors, a transmission or gear reduction unit 52 driven by each motor, and a pinion secured to the output shaft of each unit 52 and engaged with the ring gear 48. This mechanism is especially adapted to drive a thirteen foot diameter wheel at a peripheral speed in the order of about 140 to 160 feet per minute, which I have found to be a highly elficient wheel speed.

The wheel per se, as best shown in FIGURES 2 to 8, is comprised of the axle 36, the disc 44, a concentric annular shell 56 and a plurality of radial arms 58 extending between and secured to the front or forward surfaces of the disc and shell. In the preferred embodiments, four equally spaced arms 58 divide the wheel into four equal segments or quadrants. At its inner end, each arm rests on the wheel axle intermediate two adjacent gusset plates 46 and is secured to the disc 44 by a pair of radially spaced brackets or clamps 60. At its outer end, each arm extends into and is secured within a respective pillow block structure 62 which is secured to the shell 56. The shell 56 comprises a cylindrical wall 64 which is reinforced at its forward edge by a bead 66, a radial flange 68 at the rearward edge of the wall and a plurality of generally radial fins 70 secured, as by welding, to the inner surface of the wall 64 and the front face of the flange 68. In the embodiment illustrated herein, the shell is thirteen feet in diameter and is constructed from identical segments or quadrants in accordance with the division of the wheel by the arms 58. Each end of each segment is provided with a triangular gusset 72, by means of which the segments are bolted together (as indicated in FIGURE 8) or otherwise detachably connected together. Each pillow block 62 is preferably located at each juncture of the wheel segments, with one part of each block being secured to a respective wheel segment. By virtue of the segmentalization of the wheel, the wheel may be assembled and disassembled in the tunnel to facilitate entry and removal of the machine, and to facilitate replacement and repair of the wheel without removing the machine from the tunnel. The fins 70 are inclined both radially inward and in the direction opposite the direction of wheel rotation as they extend toward the rearward face of the shell and to carry excavated material upwardly from the bottom of the wheel to a discharge point as the whee rotates.

To effect excavation of earth materials, the wheel is provided on its front face with a plurality of cutting or excavating elements which are secured on the arms 58 and project forwardly therefrom. These elements are of two types, which may be identified respectively as blades and cutters. The blades are shown in FIGURES 2, '3 and as being mounted on diametrically aligned ones of the arms 58, each blade comprising a mounting post 74 secured, as by welding, to the respective arm 58 and extending generally normal to but diagonally forward from the arm in the direction of wheel rotation, and a blade tip 76 mounted on the outer end of the post. Each blade tip at its outer end includes a cutting edge of predetermined width, and the blade is preferably tilted in a radially inward direction to define a clearance angle in the order of about 5 degrees. This clearance angle may be incorporated in the blade tip, in which case the post may extend perpendicular to the arm 58, or may be provided by tilting the post relative to the arm 58 by the indicated angle.

The blade posts and tips that I employ are standard articles of commerce, namely, trencher teeth, and the manufacturers thereof specify installation of the same at a cutting angle (i.e., the angle between the wall face and the plane of the blade) from 20 to 35 degrees. As thus installed, I have found that the blades will accommodate tunneling at the rate of about 26 to 28 feet per eighthour shift, that the blades have to be reversed at the end of four hours and replaced at the end of each eighthour shift, and that the blades or teeth chatter or cause the wheel to chatter, especially when endeavors are made to increase tunneling speed. .In contrast to the manufacturers recommendations and the accepted standards of the art, I have installed the teeth or blades in my machine in such manner as to have a much higher cutting angle, the specific angle being 47 /2 degrees as indicated in FIGURE 3. By virtue of this increase in cutting angle, I have eliminated blade and wheel chatter, have increased tunneling speed to 40 feet per eight-hour shift and have increased blade life by twenty times. Specifically, I have reduced blade cost from about $2.00 per foot of tunnel to about 10, cents. Also for a given tunneling footage, I have decreased power requirements by thirty to forty percent. In the preferred structure, the blade posts are all secured to the respective arm 58 at the same angle, and the arms are individually rotatable to vary the cutting angle of all of the blades to achieve best results in a particular environment.

To facilitate blade installation, I mount the blades on the arms in such manner that all of the blades collectively span the space between the disc 44 and the shell 56 without significant overlapping or duplication of effort. Specifically, I mount the blades on each post on centers spaced radially by a distance substantially equal to the product of the width of the 'blades and the number of blade carrying arms, and I stagger the blades on each arm relative to the blades on the other arms. In the preferred structure illustrated, this results in the blades being spaced apart by the width of the blade. Consequently, as depicted by the shaded and unshaded annuluses in FIGURE 2, the blades on the upper vertical arm '58 excavate certain areas of the tunnel face (the shaded annular areas) and the blades on the lower vertical arm 58 excavate the intermediate (unshaded) annular areas.

To facilitate excavation of earth, especially hard earth materials, I also provide cutters on the face of the wheel 20, the cutters being mounted on the alternate ones of the arms '58 and each comprising a mounting block 78 secured to the respective arm and a cutter or cutting tip 80 replaoeably mounted in the block, the cutters suitably comprising teeth tipped with carballoy or other hard tip material. The cutters are mounted on the respective arms 58 on centers spaced apart essentially the same distance as, and are staggered in essentially the same relation as, the blades 78, each cutter being located the same radial distance from the hub as the inner edge of one blade and the outer edge of another blade. Specifically, the cutters on the right hand horizontal arm in .FIGURE 2 are aligned circumferen-tially with the inner edges of the respective blades on the upper vertical arm and i1 9 outer edges of the respective blades on the lower vertical arm, and the cutters on the left hand horizontal arm are aligned circu-mferentially with the outer edges of the respective blades on the upper vertical arm and the inner edges of the respective blades on the lower vertical arm. Each of the cutting tips 80 is projected further forward from the face of the Wheel than the excavating blade 76, so that the cutters cut spaced circular grooves in the tunnel face in advance of the blades (see FIGURE 5) and the blades subsequently chip or chisel out the material between the grooves thereby to afford a highly efficient excavating process.

As the cutters and blades remove earth materials from the tunnel face, the material falls downwardly and rearwardly into the interior of the wheel shell at the bottom of the wheel. The fins 70 then contact this loose material, movingly guide it into the shell adjacent the fiange 68 thereof, and commence to carry the material upwardly as the wheel continues to rotate. After any given fin 70 has passed a horizontal position and is moved further upwardly to a point where (gravitational infiue-nce outweighs centrifugal force, the material carried by the fin commences to gravitate downwardly out of the shell.

To catch the material thus gravitating from the shell, I have provided the conveyor 28. The conveyor 28, the remaining details of the tunneling machine, and the mode of operation of the tunneling machine are described in detail in the aforesaid patent application Serial No. 78,487, to which reference is made for a more detailed description of the complete machine. The present application is concerned with the excavating wheel, the preferred embodiment of which has been described in detail hereinbefore.

While I have shown and described what I regard to be the preferred embodiment of my invention, it is to be appreciated that various changes, rearrangements and modifications may be made therein without departing from the scope of the invention, as defined by the appended claims.

I claim:

11. An excavating wheel for tunneling machines comprising an annular shell, a concentric circular disc and a plurality of generally radial arms extending between and secured to said disc and said shell, some of said arms carrying narrow cutter teeth and the other of said arms carrying excavating blades, said blades on said other arms being staggered relative to one another and collectively spanning the entire radial distance between said disc and said shell without duplication or significant overlap, said cutter teeth being located one each at the same radial distance from said disc as the inside edge of one blade and the outside edge of another blade and project- 6 ing further outward in the axial direction than said blades.

2. An excavating wheel as set [forth in claim 1, said blades being disposed at a cutting angle in the order of about 47 /2 degrees.

3. An excavating wheel for tunneling machines comprising an annular shell, a concentric circular disc and an even number of substantially radial arms, at least four in number, extending between and secured to said disc and said shell, alternate ones of said arms carrying narrow cutter teeth and the other of said arms carrying excavating blades of predetermined width, the blades on each of said other arms being located generally on centers spaced apart by a distance substantially equal to the product of their width and the number of blade carrying arms, the blades on each of said other arms being staggered relative to the blades on the other ones of said other arms whereby said blades collectively span the entire radial distance between said disc and said shell without duplication or significant overlap, the cutter teeth on each of said alternate arms being located generally on centers spaced apart the same distance as, and staggered in essentially the same relation as, the blades on each of said other arms, said cutter teeth being lo cated one each at substantially the same radial distance from said disc as the inside edge of one blade and the outside edge of another blade, said cutters projecting further outward in the axial direction than said blades.

4. In a rotary excavating wheel for a tunneling machine having a plurality of excavating blades projecting forwardly from the face of the wheel at respective radial spacings from the axis of rotation of the wheel whereby collectively to span substantially the entire radial dimension of the wheel, the improvement comprising disposition of said blades substantially normal to the radii of the wheel and at a cutting angle substantially greater than35 degrees and in the order of 47 /2 degrees.

5. In an excavating wheel as set forth in claim 4, said blades being disposed at a radially inwardly tilted clearance angle in the order of about 5 degrees.

References Cited by the Examiner UNITED STATES PATENTS 825,857 7/1906 Moran et a1. 29956 1,720,195 7/1929 App 299- X 2,756,036 7/ 1956 McIntyre 299--56 ERNEST R. PURSER, Primary Examiner.

CHARLES E. OCONNELL, Examiner. 

1. AN EXCAVATING WHEEL FOR TUNNELING MACHINES COMPRISING AN ANNULAR SHELL, A CONCENTRIC CIRCULAR DISC AND A PLURALITY OF GENERALLY RADIAL ARMS EXTENDING BETWEEN AND SECURED TO SAID DISC AND SAID SHELL, SOME OF SAID ARMS CARRYING NARROW CUTTER TEETH AND THE OTHER OF SAID ARMS CARRYING EXCAVATING BLADES, SAID BLADES ON SAID OTHER ARMS BEING STAGGERED RELATIVE TO ONE ANOTHER AND COLLECTIVELY SPANNING THE ENTIRE RADIAL DISTANCE BETWEEN SAID DISC AND SAID SHELL WITHOUT DUPLICATION OR SIGNIFICANT OVERLAP, SAID CUTTER TEETH BEING LOCATED ONE EACH AT THE SAME RADIAL DISTANCE FROM SAID DISC AS THE INSIDE EDGE OF ONE BLADE AND THE OUTSIDE EDGE OF ANOTHER BLADE AND PROJECTING FURTHER OUTWARD IN THE AXIAL DIRECTION THAN SAID BLADES. 